Forecast Tutorials

Online Resources

It is with great enthusiasm that we announce the search for the next Executive Director to lead Sierra Avalanche Center! Click here to view the full job posting.

The last avalanche forecast for the 2019-2020 season posted on May 3rd. Thank you to everyone who supported the avalanche center this past season with volunteer hours, donations, and/or avalanche, snowpack, and weather observations. These contributions are crucial to avalanche center operations.

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

This Avalanche Advisory was published on February 9, 2010:

February 9, 2010 at 8:04 am

Near and above treeline, pockets of MODERATE avalanche danger will form today in wind loaded areas on NW-N-NE-E aspects 35 degrees and steeper. Below treeline, avalanche danger is LOW in wind sheltered areas.

Forecast Discussion:

A weak weather system is moving through the forecast area this morning. Off and on snow showers with spotty areas of significant accumulation are expected today with most of the new snow accumulating in areas south of Hwy 50. Around 0.5 inches of new snow fell across the forecast area last night with an additional 1 to 3 inches of new snow expected to accumulate today, mainly during the morning hours. Southwest ridgetop winds increased to moderate in speed late yesterday afternoon and continued overnight. Moderate south winds are expected to occur this morning before shifting to the east and becoming light this afternoon. Expect air temperatures at the 8,000' level to rise from the low 20s this morning to the mid to upper 20s as the day progresses.

Day to day snowpack observations from around the forecast area have shown a trend of snowpack stabilization since the last major period of snowpack instability occurred Friday morning (more info). Within this overall trend of stabilization, a few small skier triggered avalanche events have been reported. On Saturday, several small skier triggered point release loose snow type avalanches just a few inches deep measuring 10' wide by 25' long occurred on Red Lake Peak (Carson Pass area) in above treeline terrain on a NE aspect 38 degree slope at 9,000'. Incomplete information was received of a skier triggered avalanche occurring Sunday in the entrance to the Cross Couloir on Mt. Tallac (Desolation Wilderness area). This is very steep and complex terrain above treeline around 9,400', generally NE aspect with micro terrain features that cover N-NE-E-SE-S aspects. A third skier triggered point release wet loose snow type avalanche occurred yesterday on Mt. Reba near Bear Valley in above treeline terrain on a SW aspect at 8,000' on a 35 degree slope. The avalanche measured a few inches deep, 40' wide and 350' long. This avalanche was triggered at a rock band which would have increased solar radiation and heat to the surrounding snowpack over the past two days. The moving snow was able to entrain recent storm snow as it moved down the slope, increasing the mass of moving snow (photos).

Avalanche Concerns:

Avalanche concerns for today focus on new snowfall. Snow accumulations will be spotty today allowing some areas to receive up to 3 inches of new snow while other areas receive only a trace of new snow. In areas that receive the upper end of forecast snowfall amounts, small slabs will form in wind loaded areas. This will mainly occur near and above treeline on NW-N-NE-E aspects in areas below cornice features. Stabilizing conditions over the past few days should keep any snowpack instability on northerly and easterly aspects limited to the new snow only, with any failure in old snow layers occurring only as very isolated events. Cloud cover through the day today should keep any warming type snow surface instabilities from occurring today on southerly and westerly aspects.

The bottom line:

Near and above treeline, pockets of MODERATE avalanche danger will form today in wind loaded areas on NW-N-NE-E aspects 35 degrees and steeper. Below treeline, avalanche danger is LOW in wind sheltered areas.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:

0600 temperature:

21 to 27 deg. F.

Max. temperature in the last 24 hours:

30 to 34 deg. F.

Average wind direction during the last 24 hours:

Southwest

Average wind speed during the last 24 hours:

20 mph

Maximum wind gust in the last 24 hours:

35 mph

New snowfall in the last 24 hours:

0.5 inches

Total snow depth:

73 to 112 inches

Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS

Resources

Search form

Search

Follow Us

Extreme Sponsors:

This website is owned and maintained by the non-profit arm of the Sierra Avalanche Center. Some of the content is updated by the USDA avalanche forecasters including the forecasts and some observational data. The USDA is not responsible for any advertising, fund-raising events/information, or sponsorship information, or other content not related to the forecasts and the data pertaining to the forecasts.